Retort furnace



Jan. 19, 1932. A. Musso 1,841,625

RETORT FURNACE Filed March e, 1928 s sheets-sheet 1 Jan. 19, 1932. A.Musso 1,841,625

RETORT FURNACE Filed March 6, 1928 3 Sheets-Sheet 2 FW. d

;///////,////////`////////// ITL' .j

mmmmmmx '7 NVENT OR 'ATTORNEY Jan. 19, 1932.

f Of/5575455 A. Musso 1,841,625

RETORT FURNACE Filed March 6, 1928 3 Sheets-Sheet 3 f/f I Q INVENTURATTORNEY Patented Jan. 19, 1932 UNITED STATES PATENT I oFFlcE vALFREDMUSSO, F EAST ORANGE, NEW JERSEY, ASSIGNOR 0F ONE-HALF TO'.WILEIIANIIII 1. BEPPE, OF NEW YORK, N. Y. i'

RETORT FURNACE Applicationled March 6, 1928.` Serial No. 259,406.

This invention relates tometallurgical reduction furnaces.

One object of the invention is to provide a furnace of the characterdescribed which )*includes an improved retort for the continuoustreatment ofthe mineral.

Another object of the invention is, to pro- Vide a retort, the gaseswherein may be exhausted at any desired pressure.

Another object of the invention is 'the provision of a furnace of thenature set forth comprising improved means for externally firing theretort.

' A further object of the invention is to produce a furnace of the typespecified wherein the setting of the retort co-operates therewithtofurnish a substantially gas tight compartment about the retort at theopenings of the latter for obviatlng leakage of al1' i' 20 thereinto.

Still another object of the invention is the production of a furnace ofthe nature referred to in which an improved seal is provided at. theopening of the retort.

A still further objectof the invention is to create a furnace of thetype mentioned in which a uniform temperature gradient may be maintainedalong the retort.

Further objects will be seen to reside in the provision of a furnacehaving an externally fired retort in which the retort and furnace liningare made of suitable refractory material to withstand the temperaturegenerated, and the furnace lining to sustain the pressure of thecombustion gases; in which the retort is of a rotary type and includesmeans to scrape the interior wall of the retort and to aid in the mixingof the mineraltherein; and in which the fuel is consumed according tothe principle of surface combustion in improved blocks of refractorymaterial; the feeding of the fuel being preferably taken care of byautomatic temperature control; and in which an improved system for thecirculation of the combustion gases about the retort is provided; and inwhich the volatilegases generated in the retort are withdrawn at the lowtemperature end there- Tn order to indicate the practical coaction andthe functional relationship of the parts ofthe apparatus, and also byway of general description, reference may advantageously be had to themethod of `use and the results obtained by the invention. The sameisparticularly adapted for the reduction of ores by coal or othercarbonaceous materials out of contact with air and without thedeleterious iniuence of the presence of combustion gases.` Therefore aretort is provided which is h eated without combustion therein, andpreferably externally. The gases generated by the reduction are rapidlycontinuously withdrawn as fast as generated` by means of pumps or thelike, and causing a decreased ambient pressure in the retort. Hence thelatter must be sealed tight, and as the charge is continuously fed intoand out of the retort simultaneously with the forcible exhaustion of thegases, the retort has means to permit such movement of the charge with-vout entrance of air. As the chargeis in finely divided form, andconstant agitation thereof is necessary, the retort is preferablyrotatable and may be inclined at an angle to the horizontal so that thecharge is simultaneously uniformly agitated and fed through the retort.The exhaustion of the gases from the retort is preferably spaced fromand inde, pendent of the movement of the finely divided charge forassuring uniformity in operation and reliability in control. The retortrotation requires a relatively light retort, although the apparatus isintended for large scale industrial application; therefore the retortincludes a metal component or may be wholly made of metal for combinedstrength and lightness. Moreover, the transmission of heat into theretort, as from external .heating means is thereby increased. Formaximum eiiciency of heat transfer, a highly radiant or incandescentheating means, operating as by surface combustion may be employedoutside of the retort, and which may thus consume the gases generated inthe retort itself. To prevent burning the retort, the heating means isspaced along the retort wall to maintain temperatures thereininsuflicient to melt the metalor gangue. Unir form peripheral heatinglmay be obtained by the provision of circular heating means, which may,moreover, be arranged to prevent iame contact with the retort. A nautomatic temperature control may be utilized coordinated with thecharge feeding and the exhausting meanswhereby the exhaustion of gasesfrom the retort is regulated in proportion to the generation of gases,and to mantain a predetermined general pressure-temperature relationshipin the retort. By arranging the heating means to afford a temperaturegradient, the reduction of the ore gradually increases to a point ofsubstantial completeness, and the gases generated may, in course ofexhaustion serve to impart heat to the incoming charge. Thus a solidcarbon reduction of an ore may be quickly and completely attained undera reducedpressure ambient with constant removal of all gases as fastformed and under low temperatures insufficient to melt the metal organgue produced. Other features and functions of the apparatus are moreparticularly described ence characters throughout the several views,

and in which- Figure 1 is a sectional elevation of a furnace embodyingthe invention.

Fig. 2is an enlarged fragmentary section showing details of the retortseal.

Fig. 3 is a similar view showing the firing means.

Fig. 4t is a similar View showing the low temperature end of thefurnace.

Fig. 5 is a similar view of the intake end of the furnace.

Fig. 6 is a front elevation of the furnace.

Figs. 7 to 10 are enlarged sectional views taken on corresponding linesof Fig. l.

Fig. 11 is an enlarged vertical sectional view taken online 11-11 ofFig. 1 and showing a drive for the retort. Fig. 12 is a verticalsectional view taken on line 12-12 of Fig. 3.

Fig. 13 is an enlarged fragmentary sectional view of a portion of theapparatus shown A in Fig. 1.

The advantages of the invention as here outlined are best realized whenall of its features and instrumentalities are combinedin one and thesamestructure, but useful devices may be produced embodying less thanthe whole. l

It will be obvious to those skilled in the art to which the inventionappertains, that the same may be incorporated in several different'constructions. The accompanying drawings, therefore, i's submittedmerely as showing the preferred exempliiication of the invention.

The herein described furnace is particularly adapted for use in theinvention on a process of mineral reduction and metal extraction asdescribed in my co-pending applicatio-n for patent, Serial No. 208,103,filed July 25th,

' cous products of the reduction and the volatile substances liberated.v

Referring in detail to the drawings, 15 denotes a. furnace embodying theinvention. The same includes the walls and roof 16 of the furnace madeof a high temperature materi al, as for example, silica, and restingupon a concrete floor 17. Within the furnace is mounted a cylindricalretort 18, atvone end of which is a hopper 19, and at its other end adischarge device 20. IThe said hopper may receive the pulverized mineraland coal according to the process hereinbefore mentioned.

rlhe retort or heating chamber 18 is coaxial with the furnace chamber 21and is of smaller diameter than the same to provide an annular firingspace. rlhe said retort may be made of any suitable material, as, forexample, mild steel which has been chromoplated, or also of a chromealloy steel. The

\ said retort is rotatable and is likewise downare providedthatconstitute a'slip connection 23 aording/ substantially gas tightcommunicationbetween the retort and the hopper.

ylnthe bottom of the hopper' is a feed screw 24k mounted ona hollowshaft 25. vThe said hollow shaft 25 is secured tothe retort by aninternal bracket 26 so that the screw 24 rotates in unison with theretort. At its other end this shaft is journaled in the bearing 27 ofthe hopper. An exhaust pipe 28 for gases generated in the retort mayextend through thesaid hollow shaft, whereby the gases inthe retort maybe rapidlyI withdrawn the firing chamber. The said plate is formed withan annular groove 30 to receive the edge of the enlarged cylindrical endextension 31 of the ret/ort. The said extension 31 constitutes apositive-acting rotary conveyor, being provided with spaced plates 32that form a series of pockets' 33 disposed about theaxis lurality ofcircular wall of the rotor. A members 34 are rigidly secured to theplate 29 and form closures for the pockets 33. The said members 34 areconnected together by a cover plate 35`for'the retort, which' plate isin spaced substantially parallel relation to the end plate 29. The plate35 is formed with a bottom opening 36 that gages and regulates the flowof mineral from the retort into the pockets 33. For adjustment of thematerial from the retort, the gage plate 35 is vertically movable,^ormay be replaced by another similar plate having an opening 36 of adifferent area. t will be seen from Fig. 9 that thev conveyor plates 32form a closure with the circular plates 34 that substantially preventsair from flowing into the retort through the discharge device. Thepockets 33l raise the material therein to the top of the device 20,after which this material is dumped into veyor, havingsimplitied andimproved coac tion with the heating chamber. l

It will be -understood that the device 20 can be used also at the intakeend of the ed through the plate 35. The screw and the device 20 may bothbe regarded as representing positive conveyors'that rotate with theretort. v A

To scrape from the wall of the retort any material that may adherethereto, a stationary shaft 38 is extended centrally through the retortand is journaled onbrackets 39 secured thereto. The said shaft projectsthrough the plate 35 and is secured at one of its ends in the end platebearing 40. Where the shaft passes through plate 35, a slot may beprovided if vertical adjustment of the said plate is desired asaforesaid.

Extending downward from the shaft 38 at an angle with the vertical are aseries ofarms 41 spaced yalong the shaft. To the lower end of said armsis attached a mixing and scraping device which may take the form ofacontinuous chain or flexible mat 42 that rests on thev bottom of theretort. With the latter rotating in the direction of arrow a, the saidmat partly depends from the arms 41 toward the vertical central plane ofthe retort. .Thus the mat effectively scrapes loose from the retort wallany adhering material, and at the same time aids in the mixing of theheaped material M in the retort.

The furnace is fired by surface combustion. For this purpose masses ofporous refractory material are disposed circumferentially about theretort to impart heat thereto from all sides with substantialuniformity.

Y The combustion gases on leaving the masses of refractory material arecaused to circulate about the retort to further impart heat thereto.Spaced burner nozzles are arranged in any desired number to dischargegas and air under pressure into the masses of refractory, and with theobject of obtaining a substantially even radiation of heat therefrom, onthe retort. p Further, the combustion meansr is so constructed, that theburning gases substantially permeate all parts of the ,y refractory. Onleaving the refractory masses, the gases are caused to travel therefromalong the retort for uniformly heating the same in conjunction with theaction of the refractory masses on the retort.

The refractory masses y43 are made of any suitable porous material andmay be of ring form, coaxial with the furnace and seating A against theinner wall of the chamber 21.

The said masses 43 are in spaced relation at theirv inner peripherieswith the wall of the retort to avoid corrosive action on .th

latter.

`The material of which the said refractory consists may be graphitemixed with tar and calcined to drive oft' the volatile constituents ofthe tar, thus leaving a porous block. Then again, carborundum'or alundumrefractory may be formed into a ring.

Each of the rings 43`forms a high temperature combustion chamber beinginclosed on all sides except at one portion which forms an outlet 44 forthe gases. Preferably the inclosu're aforementioned is formed by glazingthe said ring.

Although the heating rings exemplify the preferred embodiment of theinvention, it will be appreciated that surface combustion can also bepractised in other ways Well known in the art, and the retort heated ina compact furnace out of Contact with the flame, by direct orsemi-direct radiation, with or without contact with the products ofcombustion. Theprimary object is to obtain uniform heating peripherallyand longitudinrlly of the retort.

The porosity of the ring and the voids therein are predetermined topermit a desired quantity of fuel to be 'consumed therein and to passtherethrough at a given pressure. Since the gas is burned with but 1%55. 'resisting material and project from the nace wall into pro-ximityto the retort. Co-

of excess oxygen, combustion proceeds with explosive velocity, and theflame will be .slightly reducing to obviate oxidation ofthe retort.

Communicating with each ring 43 is a burner 45 having a plurality ofnozzles 46 branching therefrom in opposite directions to inject the gasand air into the ring. The colmbustion thus takes place in two streamsof flame moving upwardtoward the outlet 44. The mixture of gas and airis discharged from the burner nozzle at a pressure of approximatelyfifteen pounds per square inch, and th-e burner is carefully packed withfire clay 47 and the like, or other insulating material. In this wayconcentration of heat at the burner is avoided. y

In the furnace chamber 2l the pressure of flue gas is considerable andmay be as high as severalpounds per squareinch. To take care of thispressure, the inner wall of the said chamber is glazed, rendering thefurnace wall substantially impervious to the flue gas.

Gas and air are fed through separate pipes 48 and 49 respectively into acentral mixing chamber 50, from which they -pass through a. butterflymixer 5l into al burner 45. The said butterfly mixer may be of anysuitable type but preferably includes a fan (not shown) which is rotatedby the thereon impinging air and gas and serves to thoroughly intermixthem.

An automatic temperature control 52 may be provided operating with theusual thermocouple 53 to control the supply of mixture fed to the burnerby "means of a valve 54.

Any other'suitable type of burner and control therefor can be useddepending, in part, upon the method of firing the furnace.v

By means of the said temperature control and the spacing of thecombustion blocks as shown, a desired temperature gradient can be easilymaintained in the furnace, this ranging from 9500 C. as a maximum to approximately 28 C. at the retort inlet. Also economy in operation of thefurnace is obtained, this result being aided by the fact that the gasesgenerated in the retort are exhausted at the rear end thereof throughthe aforesaid suction pipe 28.

The gases leaving the refractory blocks through the outlets 44 thereinare caused to circulate about the retort by means of baffles These aremade of any suitable leat actling with these baffles is a flue by-pass56 *intheroof of the furnace whereby, after circulation of the gases hasoccurred, the same are rapidly transferred to circulate about the imaterial receiving end of the retort soy that the available-heat of thefuelis rendered as high as possible. f

vSecured about*` the said retort are a plurality of flanged members 57that have sliding sealing contact with the baffles 55.

Between the first two combustion blocks' 43a and 43?) at the hightemperature end of the furnace is an annular passageway 58 into' ingwith one of these baffles is'another upward extending baille 55a, sothat an annular portion 60 of the furnace is shut off from thecombustion gases. rlhe arrows clearly indicate the circulation of theflue gas.

Between the combustion blocks 430 and 43d, a plurality of downwardextending baffles 55 are provided. A passage 6l connecting with thebypass 56 is formed between the block 43d and the adjacent baffle.Coacting with the last mentioned baffle, is an upward extending baille55a, so that the flue gas from block 430 is caused to circulate twicedown and up before entering the by pass 56.

Beyond the combustion block 43d, but in proximity thereto are aplurality of spaced downward extending baflles 55 with one of whichcoacts an upward extending baffle 55a. Between the said baffles 55therecommunicates a passage 62 throughA which lue gas from block 43d passesinto the flue by-pass 56. An annular passageway 63 is formed between thesaid coacting baffles on one side and engaging baffles 64, 65 on theother side. The function o f this passageway 63 will be hereinafterdescribed. Beyond this passageway 63, the iiue by-pass 56 dischargesthrough an opening 66 into the low temperature end of the furnacechamber.

The said low vtemperature end of the furnace chamber is broken by aseries of uniformly spaced downward extending baffles 67 and a similarseries of upward extending baffles 68. The baffles 67 and 68 arestaggered with respect to'each other so that a uniform and continuouscirculation-of flue gas about the retort is insured. The flue gas isfinally discharged through a flue 69.

It will be understood that while reference has been made herein to aspecific baffle construction and arrangement, the same is capable of ahigh degree of variation as is well known in the art, within the scopeof the invcntion.

It is seen that this furnace is through the circulation of gaseshereinbefore described, particularly adapted for producing auniaccordingly provided.

To afford support tothe retort intermediate of its end bearings theretort is surrounded with rings 70 of metal, o'r the like, which seat onspaced rollers 71. Thissupporting construction is housed in the annularpassages 60 and 63. Plugs 72 of re clay or similar material areremovable for inspection or repair of the rollers.

To rotate the retort, any suitable drive may be provided, as shown inFig. 11. A motor 7 3 by means of reduction gearing 74 turns a main gearthat extends around the retort in proximity to the hopper.

The invention thus produces an improved heating chamber or retort, fromwhich the gases may be withdrawn rapidly and exhausted at any desiredpressure, to aid the react-ion and the obtaining of a comparatively pureproduct, and in which the operation is continuous and uniform both froma mechanical and chemical viewpoint, the heating being uniform and even,and the temperature gradient accurate, the invention being adapted forlong use with a minimum of inspectionrepair, or cleaning.

Various changes and modifications can be made in the invention, theconstruction shown being intended in an illustrative not in a limitingsense, and it will be appreciated that within certain principles of theinvention, various objects may be substituted for the retort, and theclaims are to be construed according to the spirit of the invention, theterminology being relied on to clearly define the invention. c

I claim.:

l. A device? of the character described, including a furnace, a retorttherein having a receiving end and a discharge end, refractory materialinV the furnace, and spaced means to raise the refractory toincandescence to form a series of zones radiating heat von the retort atthe portion thereof toward the. discharge end, and baliies between theretort and the furnace wall and intermediate of said zones, there beinga by pass inthe furnace to cause the baflled combustion gases to flowtol the other portion of theretort.

2. device of the characterl described, including a retort, a positiveconveyorwithin the retort coaxial therewith to move a chargelongitudinally of the retort, unitary means to rotate-the retort andthe-conveyor, said conveyor including a plurality of pockets, and arelatively stationary closure means for the pockets, saidmeans beingconstructed to permit materials in the retort to enter a lower pocketand to discharge the materials from an upper pocket.

3. A device of the character described, including a retort, a positiveconveyor substantially concentric with the retort to move a chargelongitudinally with respect to the retort, and to rotate the conveyorand the retort at the same speed, and other means to close the pocketsat apredetermined portion of the path of travel.

4. A device of the character described, including a rotary retortfarelatively stationary transverse means including a drum therefor, androtary means along the edge of the drum forming therewith a closure forthe retort, said rotary means having a plurality of recesses angularlyspaced around said drum and closed thereby, each of said recessescoacting with the drum to receive a charge from the retort at one sideof the said drum, and discharging-the said charge in its high positionon the other side of said drum.

5. A device of the character described', including a furnace, a rotaryretort therein, the furnace having a mass of porous refractory inproximity to the retort and extending therearound, but having aclearance space with the retort, and means to internally fire the saidmass.

6. A device of the character described, including an elongated retort, afurnace enclosing the same, internally fired elements spaced along theretort on the outside thereof, at one end Aportion of the retort, andmeans. to receive the products of combustion at a plurality of points inproximity to said ele-v ments and discharge the same for circulationabout the other end portion of the retort.

7. A device of the character described, including an elongated retort, afurnace enclosingthe same, internally fired elements spaced along theretort on the outside thereof, at one end portion of the retort, bafllesfor the products of combustion intermediate of said elements, and meansto receive the products of combustion at a plurality of pointsinproximity to said elements andv discharge the same for circulation aboutthe other endV portion-fof theretort.

8. A device of the character described, including a retort, means toexternally heat the same, means to feed a charge into the retort at oneend of the same, means to discharge the charge at the other end of theretort, and means at the intake end of the retort to with-I draw gasesfrom the retort, the means for heating the retort including firing meansat the discharge end thereof, and means to circulate the products ofcombustion of the firing means about the inlet end'of the retort.

9. A device of the character described, in-

cluding a furnace chamber, an elongated retort therein, means to feed acharge into the retort at one end thereof and-to withdraw the chargefrom the retort at the other end thereof, combustion means in thefurnace chamber at the discharge end portion of the retort at pointsspaced lengthwise of said portion to heat the same, the products ofcombustion iowing to the inlet end portion of the retort, and aplurality of spaced baiiies at said inlet end portion to cause theproducts of' combustion to circulate around the retort.

10. A device of the character described, including a furnace, anelongated retort therein, the retort having a comparatively lowtemperature end and a relatively high temperature end, and combustionmeans at'the high temperature end, the furnace having a by pass in thewall thereof to cause the products of combustion to flow to the low temperature end of the retort.

11. vA device of the character described, including a furnace, anelongated retort therein, the retort having its ends at differenttemperatures, combustion means at the high temperature end of theretort, and channels for the products of combustion between the retortand the wall of the furnace, the furnace having a by pass communicatingwith the channels to receive the products of combustion therefrom andcause the same to flow to the low temperature end of the retort.

12. A device of the character described, including a furnace, a retorttherein, refractory tubes in the furnace extending inward of the furnacewall, and combustion means to internally fire the tubes, said tubesbeing spaced to provide radiation on the retort from the walls of thetubes facing the retort as well as from the side walls of said tubes,said tubes being filled with porous refractory material.

13. A furnace for reducing iron ores mixed with carbonaceous fuels in asubstantially air tight retort, at temperatures which will not causecombustion in the retort or melt the iron, including means for feedingthe materials tothe retort and discharging same, means for keeping thematerials mixed, heating means for said retort of refractory materialsto be heated to incandescence, means to regulate the flow of materialsinto and out of the retort, means to continuously exhaust the gasesdeveloped in the retort from the materials being treated therein, andmeans to regulate the flow of heat producing elements to the refractoryheating means, coordinated with the heating means to produce andmaintain predetermined temperature limits in the retort.

14. A furnace for reducing iron ores in a substantially air tight rotaryretort, external heating means of incandescent refractory materials,means to control the combustion of combustibles and air therein, withmeans to continuously exhaust the gases developed in the retort frommaterials therein, means for feeding the materials into and out of theretort, means to apply the heat to the retort in a rising temperaturegradient from the inlet end of the retort to the outlet end, therefractory heating means being spaced away from and along the retortwalls.

15. A furnace for reducing metal bearing ores, consisting of asubstantially air tight retort, enclosed therein, heating means beingprovided of refractory materials in which combustion takes place undersurface combustion temperatures, means to pass the hot exhaust gasesaround the retort after passing through the refractory heating means,means to control the flow of combustibles and air to produce andvmaintain the predetermined temperature limits, means to control,agtate, and feed the materials into, through and out of the retort,means to continuously exhaust the gases developed in the retort from thematerials being treated therein as fast as developed.

16. A substantially air tight retort and enclosed elongated tubularcombustion heating means for heating the retort by radiation, theretort` being out of contact with the burning gases in the heating meansproducing the heat, and with the means in which the combustion is takingplace, said heating means being spaced away from and along the retortwalls to produce and maintain uniform heating conditions, the heattransfer being by conduction and radiation to the retort andthematerials therein under treatment, and means to control iow of air andfuel gas to produce and maintain a temperature gradient in the retortand materials being treated.

17. A substantially air tight retort and enclosed combustion heatingmeans therefor of sutlicient length to afford a substantial travel forthe fuel consumed therein, the materials being heated in the retort, andthe retort being out of contact with the burning gases in the heatingmeans producing the heat, and with the means in which the combustion istaking place, said heating means being spaced away from and along theretort walls to produce and maintain uniform heating conditions, theheat transfer being by conduction and radiation to the retort and thematerials therein under treatment, and associa-ted means forcontinuously charging and discharging the materials being treated, andmeans to continuously exhaust the'/ gases developed in the retort frommaterials being heated.

18. A furnace for reduction of metal bearing ores having an externallyheated retort, in which the retort is made of materials capable ofwithstanding high temperatures, from heat developed in refractorymaterials surrounding the retort, enclosing walls for therefractory'materials sustaining the pressure of the combustion gasesburning in the refractory with surface combustion, and the temperaturescausingincandescence in the refractory material surrounding the retort,the refractory heating materials and enclosing walls being spaced awayfrom and along the walls of the retort in which the materials `to bereduced are being treated. l

19. A furnace for reducing metal ubearing ores including a retortexternally heated, by

' '..nieans of refractory materials spaced away i rounding theretort andthe exhaust gases therefrom to flow towards the intake end portion ofthe retort on the outside of the walls of the retort shell.

20. An apparatus for ,the low temperature reduction of iron ores withsolid carbonaceous fuels intimately mixed therewith, including a rotaryretort, automatic means for rotating the same, the retort having means,

associated therewith for moving the charge into and out of the retort,said means being co-ordinated with the retort to operate according tothe speed of rotation of the ulatter, means extending in a curved linearound the outside of the retort for externally heating the retort,means for automatically con-Y trolling the heating means, closure meansfor the ends of the retort through which the ma terials enter anddischarge from the retort,

and means for exhausting the gases from the retort through said closuremeans.

1 21. An apparatus for the heat treatment vwithout agglomeration of apulverized charge of ironY ore and coal, including a rotary metallicinclined retort of cylindrical form, a furnace enclosing said retort,stationary radiant firing means in, the furnace foruniformly'peripherally heating the retort from the outside thereof,burner means so co-ordinated with the radiant ring means and the retortas to imjpart a larger quantity of heat to the former than to the latterfor maintaining uniform heating vat relatively low temperatureon theconstantly rotating retort, stationary closure means for the ends of theretort including conveyor means for moving the cha-rgefor aA heatingthrough a required time period, and means for exhausting the gases andmaintaining a reduced pressure in the retort.

22. A device for the uniform reduction-at ka low temperature of an yironore with coal i in intimately mixedfpulverized condition, includingmeans forreceiving and constantly' agitating the charge, said meansincluding a rotary elongated retort, a furnace enclosing the same, meansinthe furnace outside of the retort `for-heating thesame with atemperature gradient from end to end of the retort, said means includingsurface combustionv means spaced from the retort for obtaining a uniformheating of the same at a low temperature although the said means are ata high temperature for efficient radiation, means forautomatically`controlling thetemperature of the heating means, means forexhausting from the retort the gases therein to produce a decreasedpressure, and means for l controlling `the movement of the charge to andfrom the retort. Y

23. An apparatus for reducing an ore with coal according to atemperature gradient 35 whose maximum temperature is relatively low,includinga furnace, an elongated retort therein, firing zones in thefurnacespaced v along the retort on the outside thereof, said firingzones having means restricting vthe spread of flame therefrom, saidfiring zones being spaced more closely near one than near the other endof the retort to produce the temperature gradient, together with meansfor feeding the charge into the retort at the p low temperature endthereof and simultaneously removing the charge from the high temperatureend of the retort for a continuous reduction of the iron ore.

24, A low temperature continuous ore rei duction apparatus, including' afurnace, a

rotary retort therein for receiving and agitating the chai'ge, meansco-ordinated withl said retort to operate in constant speed relationthereto for feeding a charge to and from the retort, means forheatingthe retort uniformly peripherally from the outside, said means includinga plurality of spaced firing means lthe spent gases of which fowconsecutively in the same direction in the furnace, no means in thefurnace for drawing off said gases at successive points in the pathsthereof, and other means for separatelyexhaust-y ing the gases from theretort.

25. An apparatus for the direct reduction of iron ore with coal inpulverized condition a-nd without fusion or agglomeration, but with thereduction occurring uniformly and in constant grada'tion, including afurnace, a rotary metallic retort therein for receiving and agitatingthecharge, meansto uniformly continuously feed materials to and from theretort atlopposite ends thereof, said retort being inclined forco-ordinated action with charge," means for constantly exhausting yfromthe retortthe. gases therein without withdrawing pulverized particlestherefrom, means vfor exhausting from the inlet end of the retort thegases in the. retort to reduce the pressure therein, means for uniformlyheating the retort from the outside thereof accordy termined relation tothe pressure.

26. A device including a furnace, a rotary retort therein for receivingand agitating a charge, means in the furnace for heating the retort,said retort comprising a cylinder por-- tion and a relatively stationaryend portion, and conveyor means for moving the charge with respect tothe retort, said conveyor means being of annular form and engaging thecylinder portion and the end portion to form a closure therebetween.

27. A solid carbon oie reduction device including a furnace, a rotaryretort therein for receiving and agitating a charge, high teinperaturemeans in the furnace for heating the retort from the outside to arelatively low temperature without flame contact with the retort, saidretort being made of a high temperature metal for eflicient heattransfer, means at opposite ends of the retort for uni-l formlycontinuously feeding into and discharging materials from the retort,means for exhausting the gases in the retort and reducing the pressuretherein, and means for automatically regulating the temperature, wherebya desired relation of temperature, pressure and speed of reduction ofthe ore may be maintained.

28. A device including a rotary metallic retort for large scalemetallurgical operations, and heating means therefor, said heating meansincluding firing members extending in spaced relation along the retort,and means enclosing said firing members to cause operation of the latterWithout flame contact with the retort, the enclosing means beingseparate of the retort and having a relatively tliin radiation wall oflarge area opposed to and facing the retort Wall on the outside thereofto heat the retort by radiation.

29. An apparatus for inetallurvical operations, including an elongatedretort, means for continuously charging and discharging the same,andheating means for the retort, said heating means including aplurality of firing members extending in spaced relation lengthwise ofthe retort, and separate combustion means for the several firingmembers, said combustion means including refractory enclosures ofsufficient size and area for causing the firing members kto operateWithout flame contact with the retort and With substantial radiationupon the latter through certain Walls of the enclosures.

30. A device including means for receiving and constantly stirring acharge, said means including a retort, and means for heating the samefrom the outside, the heating means including a furnace having aninternally fired enclosure extending peripherally around the retort inspaced relation thereto, and a burner discharging into the enclosure,the latter having an opening remote from the burner for passing theproducts of combustion around the retort within the chamber of thefurnace.

3l. A device including a metallic retort and means for externallyheating the same without llame contact with the retort, the heatingmeans including a plurality of spaced tubular channels extendingcircularly transversely along the wall of the retort in spaced relationthereto, and means to cause combustion in said tubular channels to heatthe same to a relatively high temperature for efficient radiation uponthe retort from Walls of said channels, said channels being of suiicientlength to cause the combustion to be terminated therein.

32. A device including a flota-ry retort, conveyor means coaxial withthe retort, said conveyor means extending along and being connected tothe wall of the retort, said conveyor means including pockets .rotatablewith the retort, and means closing the pockets but opening the same inpredetermined positions of the rotation for receiving and discharging amaterial, the last mentioned means coacting with the pockets to form aclosure for the retort.

33. A device including a rotary retort, a conveyor therein coaxial withthe retort, said conveyor including pockets rotatable with the retort,and relatively stationary closure means for the retort coacting With thepockets to close the same andopen an upper and a lower pocket forentrance of material into a lower pocket and discharge of material froman upper pocket.

34:. A device including a retort, and closure means therefor, saidclosure means including a rotary conveyor of ring form including aplurality of pockets arranged so that a pocket receives material in a10W position and discharges the material in an upper position, theclosure means having other means Wholly closing the pocket inintermediate positions.

35. A large scale metallurgical apparatus including a furnace, a retorttherein, a plurality of spaced tubular chambers in the furnaceindependent of the retort and extending along the outside thereof, aporous refractory mass filling said chambers, and firing means for theinterior of said chambers whereby al low temperature may be maintainedin the retort While operating said refractory mass at high temperatureand radiation eliiciency.

36. A device including a rotary cylindrical metallic retort, a furnaceenclosing the same, a circular refractory tubular enclosure extendingaround the outside of the retort., a mass of granular refractorymaterial Iilllng said enclosure, and means for discharging a fuel and asupporter of combustion into said enclosure, whereby the fuel isconsumed in the interstices of said mass, and the enclosure heats theretort by radiation from the wall of the former.

37. A large scale industrial ore reduction device including a rotaryretort, a hollow elongated refractory tubular enclosure outside of arelatively small section of the retort in close proximity thereto andspaced from the retort for mechanical clearance, said enclosure being ofcurved forni substantially concentric with the retort, and means forinternally firing said enclosure without iiame contact with the retort.

38. A device including an elongated rotary metallic retort, a furnaceenclosing the same, a refractory tube outside of the retort and withinthe. furnace, said tube being disposed around the retort in a planetransverse thereto, said tube being in relatively close proximity to theretort and having only a clearance spacing therewith, a porous mass ofrefractory in the tube, and'means for internally firing the tube.

39. A device including a retort, a'furnace enclosing the same, a massconsisting of pieces of refractory material, said mass having acontinuous wall inthe nature of a fused coating disposed toward theretort, and means to lire said mass within 'the interstices thereof. I

40. A device including a-retort',a furnace enclosing the same, a blockin the furnace consisting of pieces of material united by fusion at thesurface of the block lto provide an otherwise uniformly internallyporous block, and means to internally fire said block for heating theretort from the outside thereof by radiation from the block.

4:1. A device, including a furnace, an elongated retort therein, aplurality of tubular refractory rings spaced along the retort andextending around the outside thereof transvers'ely to the retort, aporous refractory mass in said rings,\and means to inject a fuel and asupporter of combustion at spaced points in said rings, said ringsheating the retort by radiation and having outlet openings for theproducts of combustion remote from said means.

42. A device including a furnace an elongated metallic retort therein, aplurality of refractory tubes extending around the retort transverselythereto around the outside of the retort out of contact therewith, saidtubes being spaced from each `other lengthwise of the retort, means toinject into thetubes a fuel and a supporter of combustion at spacedpoints in the tubes, and surface combustion means filling the tubes, thelatter having each an opening remote from the injecting means at an edgethereof and an opening in the wall,

an annular series of pockets spaced angularl around the curved Wall andrevolving wit the retort, said pockets4 being co-ordinated with thecurved wall of the closure to cause a movement of the charge in theretort from one to the other side of the said closure through theopening thereof, with the pockets successively registering with saidopening. 45. A device including a retort elongated in a generallyhorizontal direction, a furnace enclosing the retort, and firing meansfor the retort in the furnace, said firing meansincluding a tubularmeans extending around the retort in a transverse direction thereto,means for internally firing the tubular means adjacent to a lowerportion of the retort, the latter having an opening at an upper portionof the retort for discharging the burnt gases.

46. A device including a rotary cylindrical retort extending in agenerally horizontal direction, a furnace enclosing the same, means ltoconstantly feed materials through the retort, and a separate relativelystationary internally fired tubular means extending around a portion ofthe retort and radiating yheat thereon.

47. A device of the character described, including a furnace,a-cylindri.cal retort therein, arcuate refractory tubes in the furnaceextending inward of the furnace wall and transversely of the retort, andcombustion means to internally fire the tubes, said tubes being spacedfrom each other to provide radiation on the retort from side walls ofthe tubes as well as from the walls of said tubes facing the retort.

48. A substantially air tight retort, and enclosed high temperaturecombustion heating means for heating the retort at a relatively lowtemperature, the retort being substantially out of contact with theproducts of combustion, and with the means in which the combustion istaking place, and said heating means being spaced away from and in-lcluding portions spaced longitudinally along the retort walls to roduceand maintain uniform heating con itions, the heat transfer being byconduction and radiation to the retort and the materials therein undertreatment.

49. A rotatable substantially air tight re- 'zo' l tort for reducingmetal bearing ores, positive conveyor means associated with the retortto move the materials therein, and combustion heating means for theretort outside of the same, the combustion means being so enclosed thatthe retort is heated without contact with gases from the combustionmeans, the retort being out of contact with the means in which thecombustion is taking place, said heating means being spaced away fromand along the retort walls to produce and maintain uniform heatingconditions, the heat transfer being by conduction and radiation to theretort and the materials therein under treat-ment.

50. A substantiallyair tight metallic, ore reduction retort and enclosedsurface combustion heating means for uniformly heating the retort at arelatively low temperature, the retort being out of contact with theburning gases producing the heat, and with the means in which thecombustion is taking place, said heating means being spaced away fromand along the metallic retort walls to produce and maintain uniformheating conditions, the heat transfer being by conduction and radiationto the retort and the niaterials therein under treatment, and means forcontinuously charging and discharging the materials being treated.

51. A substantially air tight rotary metallic retort and enclosedsurface combustion heating means therefor, the retort having stationaryend Walls and being out of contact with the burning gases producing theheat, and with the means in which the combustion is taking place, saidheating means being spaced awa from and along the retort side Walls toro uce and maintain uniform heatin conditions, the heat'transfer beingby con uction and radiation to the retort and the materials thereinunder treatment, and means for continuously exhausting the gasesdeveloped in the retort from the materials being treated as fast asdeveloped and to maintain any desired pressure in the retort, said meanscommunicating with the retort through a stationary end wall.

52. A device of the character described, in cluding a furnace, an orereduction retort therein,vthe Wall of which includes a metal component,the furnace wall having hollow portions', a mass of porous refractorymaterial associated with said hollow portions through which refractorythe combustion gases flow without flame contact with the retort, meansto internally fire said hollow portions with the fuel burning in therefractory material with surface combustion and the said materialradiating heat on the retort, and automatic temperature control meansfor regulating the supply lof fuel to the firing means.

53. A device including a chamber having a circular upright wall membertherein, the

periphery whereof is spaced from the Wall of the chamber, and a rotaryannular conveyor' having a plurality of pockets, said conveyor extendingaround the outside of the periphery of the member with the pockets insubstantial contact with said periphery, certain of said pocketscommunicating with the space in the chamber on opposite sides of saidmember.

54. A` large scale industrial heating apparatus including a furnace, anelongated chamber therein, and internally fired granular` refractorymeans in the furnace extending around the chamber in a plurality ofplanes spaced longitudinally of the chamber and transverse to thelongitudinal axis thereof, whereby the incandescent heat obtained insaid refractory means produces a relatively low temperature in thechamber.

55. An ore reduction apparatus including a furnace, an elongatedinclined retort therein, means for continuously feeding a charge intoone end of the retort and out from the other end thereof, said meanscoacting with theretort to seal the same against entrance of air, meansfor heating the retort Without combustion therein, the heating meansmaintaining the retort at a relatively low ,uniform temperature, andmeans spaced from and independent of the feeding means for exhaustingfrom the retort the gases therein.

56. An ore reduction apparatus including a retort, means for feeding acharge into and out ofthe same at opposite ends of the retort, means forheating the retort along an arcuate zone extending around the retort,and means for exhausting from the retort the gases therein, theexhausting means being v substantially uniformly spaced from the heatfing means.

57. An ore reduction apparatus including a retort, means forcontinuously feeding a charge into and out of the retort, means forheating the retort to produce a volume of gases therein dependent uponthe rate of feed and the temperature of the heating means, and means forexhausting the gases from the retort, the heating means beingco-ordinated with the feeding and the exhausting means so that theexhausting means normally maintains a reduced pressurein the retort.

58. An ore reduction apparatus including means forreceiving andconstantly agitating a charge, said means including a retort, means forcontinuously feeding the charge into and out of the retort, means foruniformly peripherallyheating the retort at a relatively lowtemperature, means for positively exhausting from the retort the gasestherein, and means for automatically controlling the heating means tomaintain a predetermined temperature-pressure relation in the retort.

59. An ore reduction apparatus including means forreceiving andconstantly stirring a charge, said means including a retort, means forcontinuously feeding the charge into and CII out of the retort atopposite ends thereof, means for heating the retort according to atemperature gradient, means for forcibly exhausting from the retort thegases therein, the temperature l gradient of the heating meansincreasing from the inlet to the outlet end of the retort, and theexhausting means having such communication With the retort as to causegases in the retort to flow toward the low temperature end thereof.

60. A device of the character described including a furnace, a rotatablemetallic retort therein, said retort being adapted for use in theindustrial reduction of ores mixed with coals or similar lcarbonaceousmaterials, the retort having a Wall all portions of which are spaced ata comparatively large distance from a central point Within the retort,radiant heating means disposed at a plurality of points about theoutside of the retort to uniformly heat the same, automatic means tocontrol the flow of combustibles to the heating means, co-ordinated withmeans controlling the flow of materials into, through and out of theretort, and coacting automatic means for forcibly and continuouslyexhausting all gases as fast as formed, whereby maximum temperatures inretort are maintained below the melting points of solid materials beingtreated in retort, under conditions therein.

In testimony whereof I aflix my signature.

- ALFRED MUSSO.

